This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of the Type 1 Diabetes Genetics Consortium is to organize international efforts to identify genes that determine an individual's risk of type 1 diabetes. 1. To ascertain, study and establish a renewable source of DNA on 3000 families with at least two type 1 diabetic children for studies to map genes that affect the genetic risk for type 1 diabetes (affected sib-pair families); 2. To create a database for the scientific community with clinical, genetic (HLA, CTLA4, genome screen), and medical history information that would facilitate the search for type 1 diabetes susceptibility genes; 3. To provide a centralized DNA repository to allow targeted studies of genetic structure and function for type 1 diabetes, its complications, and other autoimmune diseases; 4. To evaluate opportunities to extend the results of research to develop methods of risk prediction, prevention and therapy in the area of type 1 diabetes, its complications, and other autoimmune diseases.